Which president was assassinated by a supporter who did not receive a government job after the presidential election?

answer; /// i believe that the correct answer is (d)the huang he river valley;

true, they can both only can be studied with ancient text.

since our new president elect donald trump is about to come into office, and since he is stating diferent signs about enforcing immigration laws, he has persuaded people into beliving that immigrants are the reason for crime & terrorism (of course thats only an example, there are many more reasons why but you probably get my idea).

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the columbian exchange, also known as the columbian interchange, named for christopher columbus, was the widespread transfer of plants, animals, culture, human populations, technology, and ideas between the americas, west africa, and the old world in the 15th and 16th centuries, related to european colonization and trade following christopher columbus's 1492 voyage. invasive species, including communicable diseases, were a byproduct of the exchange. the changes in agriculture significantly altered and changed global populations. the most significant immediate impact of the columbian exchange was the cultural exchanges and the transfer of people between continents.

the new contact between the global population circulated a wide variety of crops and livestock, which supported increases in population in both hemispheres, although diseases initially caused precipitous declines in the numbers of indigenous peoples of the americas. traders returned to europe with maize, potatoes, and tomatoes, which became very important crops in europe by the 18th century.

the term was first used in 1972 by american historian alfred w. crosby in his environmental history book the columbian exchange. it was rapidly adopted by other historians and journalists and has become widely known.